Not having seen the article, do they provide any evidence for that, or do they just assert it as a fact? I have seen the statement made that giraffes cannot swim, but wondered how that was tested, and have never seen any specific evidence cited.

For apes, on the other hand, there is abundant observational evidence that they are unable to swim, as mentioned in the follow-up thread here, (which has the incredible distinction of containing my very first post on the SDMB. )

So does the article state that Mr. Fish actually observed a giraffe keeling over in water that was too deep to wade in? Or might he have just been speculating?

Given the fact that in the other thread it was established that such unlikely critters as sloths, armadillos, moles, kangaroos, elephants, and even bats can swim, I'm not prepared to accept the proposition that giraffes can't until someone actually tosses a few in the (very) deep end and records what happens (as Dex says, equipped with white lab coats and clipboards ).

If you're a giraffe, why would you need to learn how to swim? Just walk on the bottom and stick your head out. It may sound like I'm kidding, but how often would a giraffe in the wild encounter a situation where swimming would be a survival matter?

Sorry. Can't seem to make two links in one post. Something is screwy. Maybe because they come from the same general url.

This site BBC would indicate that there is film of giraffes going into a flooded river and getting half way, then coming back. They, of course, could have been pulling an Arnold and cheating by walking.

Originally posted by Arnold Winkelried If you're a giraffe, why would you need to learn how to swim? Just walk on the bottom and stick your head out. It may sound like I'm kidding, but how often would a giraffe in the wild encounter a situation where swimming would be a survival matter?

Well, the thing is, most mammals seem to manage to swim instinctively even if they haven't encountered deep water before. Jill's column established that camels can swim, even if they rarely need the ability. Likewise, I doubt that bats often paddle about for pleasure or out of necessity, yet in the other thread someone provided an observation of a bat swimming under duress. And I suspect that a dog that had never encountered deep water before would quite sucessfully and spontaneously dog-paddle if it fell off a boat.

Swimming ability is a primitive trait. As long as a mammal (1) has positive buoyancy, (2) has limbs it can move to propel itself, and (3) has a structure that allows it to keep its head above water, it should be able to swim. The main question about giraffes is whether their unusual structure would cause them to fail on provision three. While one might easily imagine this might be so, I am highly skeptical in the absence of actual observations.

The inability of apes to swim is very puzzling indeed, since as I remarked in the other thread it seems to be more psychological than physical.

Quote:

originally written by Smeghead
I hereby volunteer!! Someone provide me with a giraffe and a deep pool, and this particular chunk of ignorance shall be well and thoroughly fought!

I'm writing a grant to the National Science Foundation right now. Send me your c.v. and I'll put you down as giraffe wrangler (and I presume you can document your previous experience in the field, of course? )

Originally posted by Colibri
Jill's column established that camels can swim, even if they rarely need the ability. Likewise, I doubt that bats often paddle about for pleasure or out of necessity, yet in the other thread someone provided an observation of a bat swimming under duress. And I suspect that a dog that had never encountered deep water before would quite sucessfully and spontaneously dog-paddle if it fell off a boat.

True, but here's what I was thinking. When a bat falls into a river, it's swim or drown, so it has to swim out of necessity as you said. A bat being a flying (and tiny) creature could often find itself in a situation where it might fall into water too deep for it to touch bottom. A dog, having short legs, could easily happen upon a body of water that would require it to swim (e.g. by falling in). On the other hand, a giraffe, even if it falls into Lake Victoria, would probably be close enough to shore that it could just walk out.

samclem, the link you provide says that a BBC crew, when filming a documentary ([i]Big Cat Diary[/b]) was able to record some giraffes returning halfway after an unsuccessful river crossing, but it doesn't say if the film was included in the documentary. I don't suppose you know if [i]Big Cat Diary[/b] includes the giraffe footage.

I found a page that has photos from the documentary:Big Cat Diary - Online Gallery
but of course no mention of giraffes. I'll have to see if I can order the video somewhere.

Quite true, Arnold. I doubt that many giraffes have had much occasion to swim since the time of Noah. My main point is that the ability to swim doesn't seem to depend on learning for most mammals (with the evident exception of humans). As long as they can float and keep their heads out of water, they won't drown; and if they move their limbs in some sort of coordinated fashion, even as if walking, they will move through the water and thus "swim" after a fashion. So if you dumped a giraffe into the middle of the Atlantic, it might still be able to float and make headway, even if its ancestors haven't had to do so for a very long time.

Mind you, I'm not insisting that giraffesare able to swim, just that I'm skeptical that they can't in the absence of observations.

Smeghead, I dunno, I think I may need to find someone with experience with eucaryotes, at least.

And I suspect that a dog that had never encountered deep water before would quite sucessfully and spontaneously dog-paddle if it fell off a boat.

Eyewitness account here: I was present when my dog Bear (rest his soul) first encountered water too deep for him to wade in. In an effort to cure him of his fear of water (his dad was a retriever, fercryinoutloud!), we took him out on a pond in a raft, and tossed him in. He didn't swim. He walked across the surface, some ~20 feet to the shore. Somehow, he managed to doggypaddle so vigorously, that nothing other than his legs entered the water, and his chest was dry.

As for giraffes not being able to keep their head out of the water, how could this even conceivably be a problem for a creature with a 3-meter neck?

__________________
Time travels in divers paces with divers persons.
--As You Like It, III:ii:328

Originally posted by Chronos As for giraffes not being able to keep their head out of the water, how could this even conceivably be a problem for a creature with a 3-meter neck?

Well, this goes back to the OP, and is exactly what Mr. Fish seems to have been saying:

Quote:

originally posted by MayThe article ("The Wild File" by Stephanie Gregory, March 2001 Outside) cites "Frank Fish, an expert on the enegetics of swimming at West Chester University."

"The reason for the giraffe's inability to swim is painful self-evident: Like a keel without a hull, the long necked creature simply cannot stay upright in the water."[/i]

So apparently what he is saying is that a giraffe's center of gravity is so high that it will just pitch forwards (or sideways) and be unable to keep its head out of the water. But it seems to me that most of the weight is in the body, not the neck, and the long legs would provide something of a counterweight anyway. The center of gravity may well be fairly high in the torso, but I doubt very much it is so high that a giraffe can't stay upright in the water. I think this guy Fish is just blowin' smoke.

A difficult obstacle for giraffes is water. Nevertheless, Turner observed two giraffes on the Serengeti in broad daylight walking across a small lake. The water probably was one and a half meters deep. In south Sudan, Scherpner saw three giraffes cross an even larger tributary of the Nile. According to the statements of his native companions, these animals must have swam. It was especially strange to see their necks stretched far forward; only the upper third of the neck and the head were above the water's surface.

I interpret the last part to mean that Scherpner actually witnessed the giraffes crossing, and his native companions informed him that the river was too deep at that point for them to have been wading.

Originally posted by Colibri
My main point is that the ability to swim doesn't seem to depend on learning for most mammals (with the evident exception of humans). As long as they can float and keep their heads out of water, they won't drown; and if they move their limbs in some sort of coordinated fashion, even as if walking, they will move through the water and thus "swim" after a fashion.

I suppose I didn't address this point. I was thinking that it would be possible for a land mammal to have evolved in a land environment so much that it would have lost the ability to swim (see Mr. Fish of Westchester University).

However, your Mr. Scherpner might have seen swimming giraffes. Unless of course his native companions (that phrase sounds a little dated to me) were pulling his leg.

Don't forget the pressure problem, even if the giraffe could keeps its head above water if its body was submerged very far it couldn't expand its lungs. Surely young giraffes could encounter water deep enough to require swimming in their native environment.

originally posted by Arnold Winkelried
I was thinking that it would be possible for a land mammal to have evolved in a land environment so much that it would have lost the ability to swim (see Mr. Fish of Westchester University).

Could be, Arnold, or at least what this post from the other thread says:

(But I think Fishhead is probably actually talking about Mole Rats, rather than true gophers.)

Even a giraffe might need to swim occasionally. Ok, adults are 15+ feet tall, but there are big rivers in Africa that are probably deeper than that (Nile, Zambezi) and giraffes occur on both sides of them. Although there are several described subspecies, they don't seem to be correlated with rivers (as for example those of apes are), implying that occasional individuals get across to maintain genetic continuity.

I've been trying to dig up the original source of the Scherpner quote, without much luck. My guess it's from Cristophe Scherpner of the Frankfurt (Germany) Zoo, who published several acticles on animals in the 50s and 60s. He may have been some associate of Grzimek. Anyway, "native companions" wouldn't have sounded that dated in 1972, when Grzimek published the account.

I have to admit the Scherpner observation sounds rather odd. I would have expected the giraffe's body to float higher in the water. On the other hand, if they were wading I wouldn't see any reason for them to stretch their necks out in front of them as he describes.

Quote:

originally posted by frolix8
Don't forget the pressure problem, even if the giraffe could keeps its head above water if its body was submerged very far it couldn't expand its lungs.

Well, that might have been an issue for giant sauropods, but I doubt it's true for a giraffe. Remember its body would be at most six feet or so under water if its head were exposed, and I don't think even a human, with a much less powerful rib cage, would have much trouble breathing through a snorkel at that depth.

Originally posted by JillGat Ooooh! A new debate. Could large bronto-type dinosaurs swim?

Not a debate. There are trackways that show impressions of forefeet but no hindfeet, implying that they were mostly floating along while propelling themselves with the forefeet barely touching bottom. (Alternative explanation: they suspended their hindquarters from dirigibles. Discuss.)

The main debate is whether some extremely long-necked brachiosaurs, that stood maybe 45 feet high and had nostrils on the top of their heads, were adapted to wading in deep water. The water pressure arguement is used to contend they were not. Nowadays it is usually assumed that the long necks and forelimbs of brachiosaurs were adaptations to browsing on the tallest trees.

Originally posted by Colibri
Not a debate. There are trackways that show impressions of forefeet but no hindfeet, implying that they were mostly floating along while propelling themselves with the forefeet barely touching bottom.

Heck, I can debate that. The tracks don't necessarily imply swimming. I have found here a picture of a hippopotamus with feet barely touching the ground, and it's not swimming.

Originally posted by Arnold Winkelried Heck, I can debate that. The tracks don't necessarily imply swimming. I have found here a picture of a hippopotamus with feet barely touching the ground, and it's not swimming.

Ok, Arnold, very good. I always thought Hyacinth was cute. Now show us one of her with just the front feet touching!

But seriously, how would you know that the tracks are forefeet and not hindfeet? I thought that part of the shape of tracks are determined by the flesh covering the bones, and we don't really know what dinosaur flesh looked like (e.g. a particular dinosaur's skin could have been covered with huge fleshy warts or else smooth as snake's skin for all we know.)

The hindfeet of sauropods are quite different in structure from their forefeet. For one thing, the forefeet had a single prominent claw on the inside front toe, lacking in the hindfoot, and were also substantially smaller. In one set of tracks, found in Texas in the 1930s, the marks of the front feet alone, barely touching the mud, make up most of the trackway, but at one point there is a mark where a hindfoot touched down, and at that point the trackway changes direction. Evidently the animal was moving along by using its front feet, then kicked out with a hind foot to change course. Besides that, there are lots of other sauropod trackways in which the marks of fore and hind feet can easily be disinguished.

There is also evidence that large carnivorous dinosaurs could swim, from trackways that show just the toe tips, as if the animal was moving along in deep water by just barely touching bottom with its hind feet. In his book Predatory Dinosaurs, Gregory Paul has a highly imaginative drawing of a swimming sauropod being pursued through the water by a pack of allosaurs like a school of sharks.

Um, and Arnold? The general shape of tracks is usually determined by the underlying bone structure, and only their detail by the surrounding flesh. For example, it's really pretty easy to tell human handprints from footprints just on the basis of knowing the underlying bone structure.

A correction on the foot structure of sauropods: Instead of lacking claws on the hindfoot as I said, actually most had three large claws on the hindfoot (the other toes apparently being capped by blunt hoof-like nails). And while most had only one claw on the forefoot, a few had more. I don't know what I was thinking.

I should also acknowledge that Arnold could have a point where elephants are concerned. The fore and hind feet are quite similar in structure, and there is a large fleshy pad under the heel that makes the footprint circular instead of conforming closely to the underlying bony structure. It might actually be difficult to distiguish the prints of an elephant's forefeet and hindfeet in isolation. However, in sauropods the prints of fore and hindfeet are generally easily distinguished.

Interestingly, the "duckbill" dinosaurs (ornithopods), traditionally pictured as being semi-aquatic, probably were entirely terrestrial. As pointed out by Bakker and others, they had bony reinforcement rods in the tail that would have prevented it from being swished side to side for swimming as in a crocodile. Also, the idea that the front feet were webbed seems to be in error, based on misinterpretation of certain petrified dinosaur "mummies" that preserved impressions of the flesh on the forefoot. That is not to say ornithopods didn't ever enter the water, just that they were not adapted for swimming as formerly supposed.

Now if I had to pick an animal that probably couldn't swim it would be a stegosaur. Loaded down by bone plates, and with a very low slung head, I doubt one could have kept its head out of the water. Among fossil mammals, glyptodonts (giant armored relatives of armadillos) would have had similar problems.

Originally posted by Colibri
I should also acknowledge that Arnold could have a point where elephants are concerned.

Ah ha! I knew it! In your face Colibri! (performs victory dance)

But seriously, it seems to me that the tracks of many animals could depend on the flesh as well as the underlying bone structure. You came up yourself with the example of the elephant (which I hadn't thought of). Other suggestions: What about the gecko lizard? Or what if an octopus slithered along the ocean floor? Though I suppose an octopus doesn't really leave "tracks" per se.

Please do not construe this as meaning that I am challenging your statement about distinguishing forefeet from hindfeet in the case of sauropods.

Originally posted by Arnold Winkelried But seriously, it seems to me that the tracks of many animals could depend on the flesh as well as the underlying bone structure. You came up yourself with the example of the elephant (which I hadn't thought of). Other suggestions: What about the gecko lizard? Or what if an octopus slithered along the ocean floor? Though I suppose an octopus doesn't really leave "tracks" per se.
[/B]

Well, sure. But for vertebrates the skeletal structure of a foot is usually well enough correlated with the external form (number and length of toes, etc.) that it's pretty easy to tell what general type of animal made the track. This breaks down when we get to the fine details. For example, it would probably be easy to tell that certain tracks were made by some kind of cat, but although different species could be distinguished if one were familiar with the living animal, this could not be done if all one had to go on were the skeletons. Similarly, gecko tracks might be identified as belonging to a lizard or other small reptile, but it might be difficult to match the track with exactly which one from just the skeleton. And if one found fossil footprints of a web-footed bird, it would could be hard to distinguish a duck from a flamingo, say. (Pelicans, on the other hand, could be distinguished because the foot structure is quite different.)

And of course when you get to soft-bodied invertebrates, all bets are off. There are all kinds of fossil trackways that can only be identified as "some kind of crawling thing" - they could have been made by snails, various kinds of worms, etc. This even extends to some hard parts - there are various kinds of small shelly-type fossils that were evidently from some kind of invertebrate, but we don't have a clue as to what phylum they represent.

Quote:

Originally posted by Arnold Winkelried

Ah ha! I knew it! In your face Colibri! (performs victory dance)

Let's not get carried away, Arnold. Actually I'm having a lot of fun trying to picture what a Swiss victory dance looks like.

How many giraffes do you have to test to confirm. For example I can't swim and I know of three other people that can't you toss us in the Atlantic and we would drown. But clearly it is wrong to conclude humans can't swim.

What if you toss 3 giraffes in the
Atlantic and they drown but the forth one swims.

I'd like to state publicly and for the record, that I can in fact swim. It's not pretty, and I can't swim for long distances, but by thrashing around, I can propel myself through the water. Lacking adequate body fat, however, I don't float, so the swimming is a short-term thing at best. If I'm in a shipwreck, I'm either clinging to some flotsam or I'm going down like a groupie on Metallica's tour bus.

Thank you.

__________________http://giraffeboard.com: come for the food, stay for the conversation. (Most of the conversation is about the fact that there isn't actually any food.)

I think the part about giraffes being top heavy is not pertinent.
Any animal will make simple changes to restore its balance. In the giraffe's case it's simply a matter of lowering the head, something it does to drink anyway. Now there's plenty of "keel" in the legs.
As for standing on the bottom. that only works until you reach the center of gravity, which is probably in the haunches. After that the giraffe would float. And keeping the head straight out, moving its legs would send it forward like a horse.

This used to be a popular pastime back on the Ark. Whenever Noah or one of his boys got bored they'd throw an animal over the side and make bets on whether or not it could swim. It turns out that all animals can swim. Except unicorns.